Sixty-eight consecutive unicompartment knee arthroplasties were reviewed. Seven patients were lost to follow-up evaluation, and the review group consisted of 55 patients with 61 medial compartment replacements. Follow-up periods averaged 51 months, with a range of 24 to 70 months. All of the knees had a Robert Brigham unicompartment arthroplasty. All patients were evaluated using The Knee Society Clinical Rating System. Overall results revealed that 70% (42 patients) rated excellent, 10% (seven patients) rated good, 10% (six patients) rated fair, and 10% (six patients) were failures. Preoperative scores in the pain, range of motion, and stability sections averaged 54 points of a maximum of 100. Postoperatively, the scores averaged 87 points. Postoperative roentgenographs were evaluated using The Knee Society Roentgeno-graphic Evaluation and Scoring System. Roentgenographs revealed at least one radiolucent line in 16 femoral components and 15 tibial components, and nine in both. Four of the six failures in the series had lucent lines in both the femur and tibia. This procedure is recommended in active patients between the ages of 55 to 65 years with single compartment disease. Also, a unicompartment arthroplasty is recommended in more sedentary patients 65 years and older with single compartment disease.
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